Description: (Taken directly from the application) The purpose of the cDNA Library Core Facility is to provide reagents and technical information to a broad range of clinical and basic scientists exploring molecular mechanisms of hematopoietic stem cell growth, replication, differentiation, and survival. Three main types of reagents will be produced by this Core: 1) Production of high quality full-length cDNA libraries derived from various treated or untreated stem cell populations (initially obtained from the Cell Sorting Core), 2) Generation of genomic DNA libraries, or PCR-obtained genomic regions, from treated versus untreated hematopoietic cells, and 3) Assembly and provision of a complete yeast two-hybrid system for identifying new proteins and signaling networks. The principal reagent in the two-hybrid system is a size-selected cDNA library in the VP 16 plasmid, which will be produced from the stem cell population. The above reagents can be used to clone and identify new stem cell proteins present in limited numbers, explore specific genomic rearrangements in stem cell populations, and characterize new signaling networks within these early hematopoietic cells. Equivalent reagents are not commercially available; however, the broad array of research activities at the Hutchinson Center makes it possible to provide both the human stem cell populations and basic research skills needed for the production of both cDNA and genomic libraries. Additional reagents for investigating specific protein-protein interactions in the early stages of blood cell development also can be provided. Dr. Rohrschneider and Dr. Algate will serve as the Core administrator and principal investigator of the facility, respectively, and both have extensive experience with cDNA library production and the yeast two-hybrid system. The cDNA Library Core Facility will be housed in Dr. Rohrschneider?s laboratory, taking advantage of the existing equipment and facilities while adding those needed to accommodate external users. In full operation, the Core will produce the above reagents and skills as demanded by individual investigators and a portion of the cost recovered by user change-back fees. In addition, developmental research will be conducted to improve the existing reagents with the objective of isolating individual cDNA clones from stem cell library for production of DNA chips through the DNA chip Facility at the Hutchinson Center, headed by Dr. Helmut Zarbl.